Tappet spacer retainer



Dec. 24, 1957 R. E. TAYLOR TAPPET SPACER RETAINER Filed Feb. 16. 1956 2Sheets-Sheet 1 8 ww.: A Q ,l l if?. .o 4 w ,M 2M. 0 33 E w Lf .fo

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Auw/T United States Patent O 2,817,326 TAPPET SPACER RETAINER Ross E.Taylor, Grosse Pointe Farms, Mich., assignor to Studebaker-PackardCorporation, Detroit, Mieli., a corporation of Michigan ApplicationFebruary 16, 1956, Serial No. 565,835

8 Claims. (Cl. 123-183) This invention relates to the valve assembly ofan internal combustion engine and more particularly to a valve tappetspacer retainer for said valves.

In internal combustion engines the maintenance of proper clearancebetween the valve tappet and its actuating cam is vitally important assuch clearance must be held to close tolerance for efcient operation ofthe engine. Various means have been provided in the prior 'art forshimming up the contact portion of the tappet relative to the ends ofthe valve stems to maintain the desired clearance between the tappet andthe cam. This problem is especially acute if the spacer shim, placedbetween the ends of the valve stem and valve tappet housing, slips outof position and becomes enmeshed with the springs and other moving partsof the valve tappet assembly whereby not only is the designed clearancelost but the shim may become deposited in such a position as to hold thevalve open with an accompanying loss in power and eici'ency. Thisnecessitates expense in disassembling the engine and repairing thedamaged tappet assembly.

Although several ways have been proposed for holding the shims inposition, no device is currently known which is relatively foolproof inuse. It is therefore a principal object of this invention to overcomethe disadvantages of the prior art and to provide a retaining means forholding a spacer shim between the ends of a valve stem and the contactportion of the valve tappet that is positive in action and not likely tobecome broken, displaced, or misaligned from its designed position.

operation, easily operated, and repair.

corresponding tappet.

While the tappet spacer retainer means of the present invention is shownand described in connection with valving of an internal combustionengine having overhead studied wherein:

. Figure l is a sectional view of a portion of an internal combustionengine showing particularly the overhead Figure 5 is a sectional viewthrough the central portion of said tappet spacer retainer.

, Referring now to the drawings for a detailed description of thepresent invention, in Figure 1 the valve and valve actuating assembly ofan overhead valve internal combustion engine is shown. This view showsan engine block 10 having an associated cylinder liner 12 seated thereinand having a cylinder head 14 bolted thereto to form a combustionchamber or cylinder 16. Water passages 18 are provided to cool theengine and maintain it at operating temperature. The engine has both aninlet passage 20 through which combustion supporting air and fuel isdrawn into the combustion chamber 16 and an outlet passage 22 throughwhich exhaust gases are expelled from the combustion chamber. The inletpassage 20 and outlet passage 22 are sealed during predetermined periodsof the engine cycle from the combustion chamber 16 by poppet valves 24and 26.

As both valves are identical in construction and operation within thescope of the present invention an explanation of one valve will suce forboth and therefore only exhaust valve 24 will be discussed in detail.Valve 24 comprises a valve head 28 and a valve stem 30, which stein 30slides in a sleeve 32 seated in the cylinder head 14.

14 and encases the upper portion of A collar 36 is detachably securednear element 44 is a spacer shim 42 which is held by means of a spacerretainer 46, which forms the principal subject matter of the presentinvention.

Means are provided permit lthe ilow of combust1on supporting air andfuel to p rotated 50 is forced against and allow the passage of exhaustgases sage 22.

Clearance is provided the tappet 44 and the minimum diameter of the cam50 mass production it is necessary that a means be provided foraccurately prochamber 16 through the exhaust pasviding for the clearancein question, both when the engine is new and also when the engine isbeing repaired after wear has been encountered. The present inventionprovides for spacer shims 42 to be disposed between 'the valve stem 30and the tappet cup 44. The shims 42 are designed in various thicknessesso that the shim of proper dimension may be selected to provide theclearance required. The valve assembly is subjected to continualoscillating motion during the operation of the engine, and therefore itis necessary that proper means be provided for securely holding theselected spacer 42 in position.

The -spacer retainer 46 is oiy generallycup shape design having a base51 which has a plurality of tangs 52 directedl radially inwardly andinclined slightly outwardly from `the lplane ofk said base. It isintended that the spacer retainer 46 be formed of spring ysteel or asimilar material so that a spacer shim 42 may be snapped into positionrelative to the retainer and securely Aheld therein by the resiliency ofthe tangs 52 which engage in an,

54 that is circumscribe'd about the peannular groove rimeter of thespacer 42.

The retainer 46 has a skirt portion '56 depending from the' periphery ofthe base 51 which is provided with a plurality of longitudinallyextending slots 58 so that individual portions 55 of'the skirt 56 canbe'flared slightly radially outwardly from the base portion thereof. Inassembly the combined spacer shim 42 and spacer retainer 46 are'ttedwithinV the tappet cups 44 whereby a coaction between the taper of" theskirt portion 56 and the inclined tangs 52 results in a locking forcehereinafter described. The device is assembled by inverting thetappettcup 44 on la bench or work surface 60 and forcing the assembledspacer shim 42 and spacer retainer 46l into coacting position withinsaid tappet cup 44. A tool 62 having a head 64, preferably ofnon-metallic material, is usedto'ra-m the spacer 42 and its retainer 46into position. The head 6.4' is of such a diameter that part of itstrikesthe retainer 46 at about the centrl portion of the tangs 52 andan opening 65 in the center is adapted to iit over the spacer shim 42.

When the tool 62 forces the spacer retainer within the cup member 44 toits full depth, the spacer shim 42 strikesV the inner surface of thetappet cup 44. With the application of further force on the tool 62 thenormally inclined tangs 52 are flexed into a fiat attitude so that theyare positioned in a common plane. The deflection of the tangs 52 tendsto cause the skirt portion 560i the spacer retainer 46 to flareoutwardly to an extent greater than normal. As the skirt 56 of theretainer 46 is held in position by the internal cylindrical wall of thetappet 44, the deilection of the tangs 52 is transmitted as a forcethrough the skirt 56 against the inner wall of the tappet cup 44. Thisforce holds theretainer 46 and consequently the spacer shim 42 in thedesired location. Any movement of the tappetl 44 during the operation ofthe engine which might tend to dislodge the retainer 46 from itsposition would be countered by the force of the skirti56 against theinner walls of the tappet cup 44 and also by the action of the edge 66of the skirt 56 which will tend to dig-in and thuseven more securelyhold the retainer 46and the shim 42 inposition.

While, a retainer of particular design is shown in the drawings yanddescribed in detail, variations are contemplatedk within the scopeof thepresent invention, the above detailed description being for the purposeof presenting the preferred embodiment of the invention of thisapplication.

I claim:

l; In an internal combustion engine having cam actuated poppet valves,the combination of a cup member disposed over the stem end of saidvalveand between said valve end and said cam, a spacer shim of preselectedthickness positioned between said valve end land said cup member to'provide a predetermined clearance between said cup member and said cam,a retainer for holding said shim in position, an annular groove aroundthe girth of said shim, a. plurality of inwardly directed radial tangson said retainer intersecting said annular groove, said tangs beinginclined axially to the plane of the base of said retainer, saidretainer having a iiared skirt portion with longitudinally extendingslots, said retainer being positioned within said cup member so as to beelastically deected and thereby held in position by its own springaction.

2. ln an internal combustionengine having a cam `actuated poppet valveand a cup member disposed over the stem end of said valve and having itsbase between said cam and said valve end, the combination of la spacershim of preselected thickness positioned between said valve end and saidcup member to provide a predetermined clearance between said cup memberand said cam, a retainer for holding said shim in said position,generally cup shaped and having a iiared skirt portion, said skirtportion having a plurality of longitudinal slots, the base portion ofsaid retainer being formed of a plurality of radial tangs directedinwardly for gripping said shim.

3. In an internal combustion engine having a cam actuated poppet valve,the combination of a cup member positioned over the stern end of saidvalve and with the base thereof between said valve and said cam,preselected thickness between said valve end and said cup member andsaid cam, a retainer for holding said shim in said position, saidretainer having a flared skirt portion, said skirt portion being of suchdiameter as to create a spring it when disposed within said cup member.

4. In an internal combustion engine having a cam actuated poppet Valve,the combination of a cup member disposed between said valve and saidcam, a shim of preselected thickness positioned between said valve andsaid cup member to provide a predetermined clearance between said cupmember and said cam, a shim retainer for holding said shim in position,said shim retainer having a flare skirt portion, saidretainer beingpositioned within said cup member and of such size that the skirtportion thereof will be deiiected to hold said retainer within said cupmember.

5. A spacer shim land shim retainer, said shim being of selectedthickness and generally disk shaped, said shimhaving an annular grooveabout its girth, .said retainer being Vgenerally cup shaped and having aiiared skirt portion, .said skirt portion having longitudinallyextending slots, radial tangs onsaid retainer for holding said shim,said tangs being inclined to the base of said retainer.

6. In an internal combustion engine having a valve, a cam engaging withsaid valve, and a tappet member coacting between said cam and said valvefor holding said valve seated, the combination of ka shim, means forholding said shim positioned between one end of the valve and the tappetmember for maintaining a predeterminedy clearance between said tappetmember and said cam, said means comprising a retainer having a circularbase,` a plurality of tangs projecting radially inward from said base tosupport said shim, a skirt formed around the periphery of the base,said` skirt being divided into. a. plurality of outwardly ared sectionswhich are yadapted to engage with the inner portion of the tappet memberfor holding the shim in position.

7. A spring retainer having a domed shaped base portion and an axiallydisposed skirt portion around the edges thereof, said base portionhaving radially extending slots formed therein to kpermit axialdisplacement of the central portion thereof and said skirt portionhaving longitudinally extending slots formed therein to permit radialdisplacement of the outer end portionsY of said skirt.

8. A spring retainer having abase, `a plurality of tangs extendingradially inwardly and slightly axially from said retainer being4 a shimof' 2,817,326 5 said base and a skirt divided i nto a plurality ofoutwardly 999,941

flared portions depending from the periphery of said base. 1,017,993

References Cited in the file of this patent UNITED STATES PATENTS 5341262 976,274 McHardy NOV. 22, 1910 6 Yale Aug. 8, 1911 Ottaway Feb.20, 1912 FOREIGN PATENTS Great Britain Mar. 16, 1931

